barbet



Patented Mar. 15, 1921.

5 SHEETS-SHEET 2- I I 17 l Inventor E 19 BaJ'ZeZ v E. A. 'BARBET}TREATMENT OF PYROLIGNEOUS LIQUIDS EROMFTH'E CARBONIZATIQN OF WOOD.

APPLICATION FILED OCT-1 14, 1918- 1,371,461.

Patented Mar. 15, 1921.

5 SHEETS-SHEET 3- [m1 cm E. A. BARBET. TREATMENT OF PYRQLIGNEOUS LIQUIDSFROM THE CA APPLICATION FILED OCT. 14-, I918- RBONTZATION 0F W 00D.

Patented Mar. 15,-1921 E Shiv-70% 7' B a 31119; T I ,1

v I o o J Inv-awi'ar EflfiQrlBi' B3 16% E. A. BARBET.

TREATMENT OF P'YROLIGNEOUS LIQUIDS FROM THE CARBONIZATIOY OF WOOD.

APPLICATION FILED OCT. :4, $518.

Pamn'ieai Man 15 1921.

iwA c 5 SHEETS-SHEET 5.

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EMILE AT J'G-USTIN BARBET, F PARIS, FRANCE.

TREATMENT OF PYROLIGNEOUS LIQUIDS FROM THE CAEBONIZATION OF WOOD.

Specification of Letters Patent.

Patented Mar. 15, 1921.

Application filed October 14,1918. Serial No. 258,112.

To all whom it may concern Be'it known that I, Emits AUeUsTiN BARBET,citizen of the French ltepubhc,*r esiding at Rue de lEchelle, Paris,France have invented certain new and useiul Tin-'- provements in theTreatment oi Pyrohgneous Liquids from the Carbonization of eliminationas complete as possible of the tars in order to obtain acetates of limeor of soda as white and as pure as possible.

This invention relates to process by Which one can obtain these resultsin alcohtinuous way and to continuous apparatus designed for carryingout the said process.

In the description which follows, there is first briefly indicated thesuccession of the operations, then the main apparatus elements aredescribed more in detail in order to show how they are constructed "foranswering to the purpose aimed at.

In the accompanying drawing:

Figure 1 is a diagrammatic view of the whole plant; Fig. 2 shows, on anenlarged. scale, the tar removing apparatus Fig. 3 is a plan view ofErplate employed in the device of Fig. 2;

Fig. 4 is a detail view of a modified and improved form of thesaturator, and

Fig. 5 is a diagrammatic view of a modification of the whole plant.

Referring to the treatment as eilccted in Fig. 1, the gases and acidvapors coming from the'retorts for the distillation of the wood enterthrough the valved hipe a into the tar removing apparatus A. Thisapparatus is so constructed as to retain the 'greater portion of thetars. From there the vapors assing through the pipe 1 are condensed in Cand cooled in I). The liquid condensedin C passes through the pipe 2 andis further cooled in D the liquid coming from D flows away through pipe3, and joining with the liquid coming from D both pass through the gagetube E are, after passing through the pipe 4:, raised by pump N throughthe pipe 5, to the upper vessel 1.

The non-condensable gases, cooled in I), pass through the pipe 6 intothe lower part of a scrubber G, in which they are washed with water,which removes the methyl alcohol which has not been condensed. Thewashed gases finally issue through the pipe 7 are forced by theexhauster J through the pipe 8 to a point of use, 0. to the burners forheating the retorts.

The water issuing from the bottom of G contains about from 1 to 2% ofmethyl alcohol; it is led by the pipe 9 to the heat exchanger 78, thenby the pipe 10 to the distilling column H the vapors pass through thepipe 1 l into the column H on the plates of which the methyl alcohol isbrought to a suitable concentration. The methyl alcohol passing throughthe -pipe 12is condensed in K and cooled in L, and passes through pipe13 to the gage tube F.:'-' The spent liquid from H is sent to-the sewerafter delivering its heat to the water entering the apparatus H in theexchanger it.

The pyroligneous condensate in the vessel I is fed by pipe 14,controlled by feed cock 2', to the heater K. and from there it goes downthrough the pipe 15 into the top of the distilling column H which isadapted to extract therefrom the methyl alcohol.

The vapors issuing from the column H are very acid. If they areintroduced in this-condition in the concentrating plates of H :1 largequantity of methyl acetate would be generated. In order to avoid this,the vapors coming from H, through the pipe 16. pass through a smallplate column I3, called the saturating column. A small quantity ofwhitewash (milk of lime)- from the vessel U goes down through the pipe17, controlled by the cock T and enters the upper part of B. In thismanner the methyl alcohol vapors are neutral when they are introducedthrough the pipe 18 at the bottom of H where they are concentrated alongwith the vapors from H The reflux from B, composed of acetate of lime,is led through the pipe 19 into the vessel X, where it mixes with theother acetate of lime produced in the manner described below.

The pyroligeneous liquid freed from methyl alcohol issues at the base ofthe column H through the pipe 20 and is then to be evaporated. A pump Ndrives it back while it is boiling hot, into the evaporator O or Theevaporatoris continuous and replaces the ordinary discontinuous systemusually called the three boiler system, and avoids N through pi eminished by that .of the 'methyl alcohol driven off in H, and on accountof this previous separation, simple evaporation can be-efi'ected in acontinuous way.

The evaporation apparatus consists of two similar tubular bodies 0 and 0each having a capacity substantially sufficient for vaporizing thetotality of the pyroligneous liquid; only one of the two bodies 0 and Ois in operation at a time, the other, during this time, being cleanedand made ready to work when the first body will become too much fouledby tar for eflicient'operation. The flow of liquid to the desiredone ofthe two bodies is effected by means of cocks or valves 39 and p for O,and p? and p for 0 The pipe 22 is a continuation of pipe 21, and thesepipes, together with the pipes containing valves 0 and p for a cross, ora four-way connection.

The pyroligneous liquid, elevated by pump 21 enters, for instance, thetubular body through the open valve p and ascends rapidly within thetubes. A violent ebullition throws a mixture of steam and liquid throughpipe go into the separator, P, which is of a very large diameter. Theexcess ofliquid goes down again through 22 and is readmitted through 12The inlet pipe isprovided with an opening 41 directed downwardly; theliquid follows the, path indicated by the curved arrow and in thisretrograde movement the tar, which is heavier than water, settles to thebottom of the lower Come from which it is drawn off through the cock inpipe 23, into the well S. The high speed of ascent of the liquid in thetubes 0 largely prevents the tar from adhering to the tubes and in anycase when the choking begins to give trouble, the tubular body 0 is putout of action and the evaporation is continued in the tubular body 0 thecover V is opened and the tubes are cleaned without waiting fortheapparatus to cool.

The separator P is provided at the top with a foam clearing and tarremoving apparatus Q so that the acttic vapors which issue from theevaporatdr are as free as possible from tar. Theyfthen pass to thesaturating apparatus B through the pipe 24.

R is a continuous saturaltor or Iieutralizer.

Everything is continuous in the whole of the process. The saturation iseffected at will, either by means of lime or of soda; the reagent iscontained in the vessel U, it flows through pipe 25 and the volume of:reagent fed is controlled by the cock T. The saturator contains severalsplashing plates, the sat uration being nearly instantaneous. Theacetate of lime or soda (in solution)=..issues through the pipe 26, andthen flows to the vessel X, and is subsequently filtered.

The saturator R, while neutralizing the acetic acid condenses but asmall fraction of the water vapor coming from the evaporator and thisexcess is henceforth neutral and entirely'free from acetic acid. Byreason of the-continuity of the operation, this available heat may beeasily used. This vapor is sent through pipe 27 to the bases of thedistillin columns H and H so that. both distillatlons are effectedentirely by this by-product steam. The heating of H is effected throughthe medium of a heat ex,- changer it so as not to dilute thepyroligneous liquid. For H a splasher will be s'uflicient. I

Any excess of steam from.R lifting the safety valve 1, which is adjustedto a pressure of about kilogram, issues through the pipe 28. It may beused for the con cent-ration of the acetate or for any other purposes inthe works.

The lime acetate solution in the vessel X is cloudy. It is sentthroughthe pum N and the pipe 29 to the filter-press l The filteredsolution flows away through the pipe 30, still lightly colored bytar,and is introduced into a continuous and methodi cal scrubber M in whichthe solution of acetate passes downwardly through a columnof liquidcapable of dissolving and retaining the tar, for example cresol or anysuitable hydrocarbon liquid not capable of mixing at all with water(totally insoluble therein) and capable of floating on the surface ofthe' acetate solution, (by reason of a density lower than that of theacetate solution) (this operation bein claimed in my co-pending caseSerial 0. 258,111, filed Ocober 1a, 1918) The. cylinder M is entirelyfilled with a divided inert material (such as broken glass or quartz,coke, etc.,) in order to increase the contact between the acetatesolution and the purifying oil. This oil enters through 31 and issuesthrough 32 to be revivified by distillation. The acetate solution entersthrough 30,'passes downwardly and issues through 33, passes through thecontrol gage tube m into the vessel 34, thence to the acetateevaporation apparatus, which ma be a tubular body similar to O-'O -Pheated by the excess steam issuing from the saturator R.

-' The purification of the pyroligneous acid by means of cresol mightalso be effected beforeits neutralization. In this case, the

apparatus M would be placed to the; left,

near the tar removing agparatus A and fed. through the pipe- 3. he gagetube m would then be replaced by the gage tube E.

Such is the whole of. the urificat-ionlprocess forpyroligneous acid; tis process is entirely continuous, as isalso the production' of gasesand vapors in the battery ofwooddistilling retorts. It is to beunderstood that it will be useful to duplicate the parts,

A, B and B, so as to be able at fixed times to take them apart to cleanthem without stopping the works.

A few supplementary remarks will now be given concerning the details ofconstruction of the tar removing apparatus and of the saturartor, theother apparatus being of better known construction.

Tar removing apparatus, (Figs. 2 and 3).The tar removing plates might beoi any suitable construction. The one here shown reduces to a minimumthe frequent and laborious cleaning operations. The construction shownin elevation and section in Fig. 2 and in plan view in Fig. 3, comprisesa concave plate (Z provided with a circular cap 6 and an axial cap f;this type of plate has the advantage of insuring a large de velopment ofthe splashing line, an easy circulation of the tar on the plate and acomplete independence between. the passageways for the gases and vaporson the one hand and the caps which cover them on the other hand. In thismanner, when taking the column apart for cleaning ready access may behad to all parts, above and below the same. The concave shape of theplates makes it possible to do away with any kind of an armature andpermits of draining in a. better manner. all the tar before taking thecolumn to pieces. For this purpose. a flap valve actuated from theexterior by means of a handle 0 is held closed during the operation andis opened as soon as the operation is over.

The lower part of the tar-removing apparatus is composed of twosuperposed chambers and ZQ in the upper chamber L, the vapors and gasescoming in, below the top of the annular cap a, are forced to bubblethrough the bath of tar which is at a high "temperature, much over C.The greater part of the small drops of tar are caught therein.

The plates arranged above these two chambers are also splashing orbubbling plates, the caps being slightly immersed in the tar.

In the plates above the lowermost, the caps are not. immersed and theretention of the tar globules is secured by the rupture of the films ofsuch globules by striking the surface of the tar bath. Finally, on theuppermost plate there is no tar. the caps acting as foam-catching orharm-breaking devices.

The plates have a second action; that of liberating the 'pyroligneousacid dissolved in the tar. The tar coming from the barrels arranged onthe retorts, enters the tar-removing apparatus at 7) on. the secondplate, from the top, and gradually overflows from plate to plate.

It resinous woods are distilled, the tarremoving apparatussimultaneously causes the pine oil contained in the tar to distil,

elimination otthe acetic acid and pine oil from the tar.

A llXB steam injector j sucks a small quantity of the washed gasesissuing from the exhauster J, gases which do not contain any oxygen andwhich mix witlrthe gases of the same composition coming through (L. Thesystem of driving back by means of an injector gives the advantage of asimultane ous heating of the tar. The mixture of gas and water vapor isintroduced into the tar by means of a perforated bubbler m; it drivesaway the pyroligneous acid as vapor, through the central passage-way Zand the whole mixed with the gases ol the retorts ascends through thecveral. tar-removing plates.

iS'utzmrzor, Fig. llr ln the same way for the tar-removing apparatusordinary cap plates might be used, but they would necessitate morefrequent and more laborious cleaning operations. For the same reasons.it is preferable to use the readily examinable caps described above. a

The admission of the reagent through the pipe 25 will be controlled bysai'npling. in the pipe 2? (Fig. l) the vapor, which must be entirelytree from acidity, this being vcritied by blue litmus paper. it is of nocouscquence it the liquid issuing through should have a theneutralization would. be completed in the vessel K. In this way there isnot much risk ol? soiling and iucrustiug the plates of ti e saturator.

in the im noved modification of the satu- .rator shown in Fig. t. thetwo lowermost plates are used for washing the vapors with water, toretain a portion of the tar, prior to the lwutralization ot' the aceticacid vapors by milk of lime. For this purpose. water is introducedthrough the valve 1?, the used water being drawn oil by vhe siphonformed of the pipe 74-36, this siphon having an upwardly extending pipe107. to prevent priming. it is accordingly possible to draw oil the mosttarry .vatcr, through the pipe 3 5.

he acetate of lime must be prevented from. mixing with the Wash Waterhndconsequenthy the acetate solution is drawn oft separately through theoverflow 0' and the bent pipe 1, pipe 26, into the (Pig. 1).

Fig. 5 illustrates an apparatus for carrying out the process in case aless pure acetate of lime would be satisfactory.

In this form of e, A designates th'e tar-removing appara. as.

.Tl'i'e satu ator ll arranged. adjacent to vessei X.

acid reactil'm; in this case.

the said apparatus and receives the vapors, freed from tar, directlythrough the pipe 35. The vapor containing methyl alcohol,

.issuing from the top of B through 39, is

condensed in C and D, the liquid containing methyl alcohol flows intothe rectifier H, H through the pipes and 9, and heat exchanger 100.

The noncondensable gases enter the scrubber Gr through the pipe 2, andthe scrubbing water passes down through the pipe 9 into the rectifier H,H The vapors of methyl alcohol are condensed and cooled at K and L. Asingle raw methyl alcohol gage tube E will be sufficient unless it isdesired to effect immediately a fractionation of the head and tailproducts, which operation is easy to do.

The acetate solution from X is pumped by N 2 through pipe 29, andfilter-press V. Before concentrating the filtered acetate solution, itmay be passed through the washing apparatus M for retaining theremaining tar by means of the cresol, as above described.

Finally, the pump N 3 sends the acetate to the single" or double eii'ectevaporator; the

excess steam therefrom may be used for heating the distilling column H,H

This form of execution of the invention is not only more simpleconcerning the construction, but is especially much more economical insteam than that illustrated in Fig. 1 and it should be preferred if thequality of the acetate is sufficient to meet the existing demand.

I claim: 1. A process of treating the gases and vapors produced in thedestructive distillation of woody material, such process comprisingcontinuously removing the major part of the tar from the vapors, whileat a temperature above the condensation point of acetic acid at theexisting pressure, continuously cooling the remaining gases and vaporsto condense out the pyroligncous condensate, continuously scrubbing there maining gases and vapors to remove the last of the methyl alcohol andto leave a combustible gas suitable for use as fuel, contintate liquorthrough a water-insoluble liquid capable of dissolving tarry materialthere from.

2. In the treatment of the gases and vapors of destructive distillationof wood, the steps of first washing the gases and vapors with tar, saidtar being, durin a part at least of such washing operation, maintainedat a temperature above the temperature at which pyroligneous acid andmethyl alcohol would be retained in substantial amount thereby, passingat least the pyroligneous acid content of said gases and vapors, whilein vapor form, into contact with an alkaline absorbent liquid to producea pyrolignite liquor, condensing methyl alcohol from the gases andvapors at a suitable stage of the process, and filter-pressing thepyrolignite liquor, and Washing the pyrolignite liquor with a liquid tarabsorbent which is-insoluble in said liquor.

In testimony 'whereof I have signed my name to this specification, inthe presence of

